The most common mascara applicator is the mascara brush. A classic mascara brush has a bristle head that comprises a collection of individual filaments disposed within a helical wire core. The wire core depends from one end of an elongated stem, while the other end attaches to a handle. Also known, are molded bristle heads, which are fashioned as a cylindrical sleeve with integrally molded bristle elements radiating from the sleeve. The molded sleeve may be slipped over one end of an elongated stem, while the other end of the stem attaches to a handle. In either case, the radially extending bristles, collectively, form a bristle head or applicator head, the “working portion” of the applicator. For a review of those brush parameters that are recognized by a person of ordinary skill in the art to be results-effective, see U.S. Pat. No. 7,465,114, herein incorporated by reference, in its entirety.
Mascara applicators that utilize individual “lash grooming elements” other than bristles, are known. U.S. Pat. No. 3,892,248 describes an applicator comprising a central shaft (or core) along the length of which rigid triangular plates outwardly project, many such plates being parallel to each other. The regularly spaced plates are reportedly suitable for loading, transferring, coating and separating. U.S. Pat. No. 4,545,393 described a bellows capable of being lengthened or shortened by the user as required. The stacked “teeth” of the bellows provide surfaces for holding mascara and the spacing between the teeth allows the eyelashes to be coated and separated. U.S. Pat. No. 5,094,254 describes a central core with a ribbed profile. The individual ribs provide surfaces for holding mascara and the spacing between the ribs allows the eyelashes to be coated and separated. U.S. Pat. No. 5,816,728, herein incorporated by reference, in its entirety, describes a beaded mascara applicator, that is a mascara applicator having one or more beads disposed on a central axle extending longitudinally from an elongated rod and handle. A first preferred embodiment comprises a single cylindrical bead molded from plastic and having a series of longitudinally spaced grooves along the length of the bead. A second preferred embodiment comprises a plurality of about 5 to 7 beads disposed on a metal axle and retained by means of a flat-headed pin. The beads are capable of individually or collectively rotating about the axle to create optimal mascara application and lash separation. Preferably the diameter of the spherical beads ranges from 0.80 to 7.0 millimeters and the length of the non-spherical beads may range from 0.80 to 9.0 millimeters. U.S. Pat. No. 6,345,626 and U.S. Pat. No. 6,691,716 disclose a mascara applicator having an array of independent discs which compress during withdrawal from a container so that excess product can be removed from the applicator by a wiper. After passage through the wiper, the discs return to their expanded position by the action of a spring. The compressing of the discs during withdrawal allows a controlled amount of product to remain on the applicator for application by the consumer, and the returning of the discs to their expanded position by the spring causes the discs to assume a configuration which allows the applicator to effectively comb and separate the eyelashes.
Heating cosmetic applicators are known, in particular, heated applicators for mascara. For example, U.S. Pat. No. 5,775,344 discloses a mascara applicator having a heat facilitating strip located within the wall of the applicator rod. The heat facilitating strip is continuously distributed along the rod or stem of the applicator. Various other heated cosmetic applicators are known in which the heating element is an extended component, continuously distributed along a rod or stem of the applicator. For example, copending application U.S. Ser. No. 12/732,835 (herein, incorporated by reference, in its entirety), discloses heating applicators that comprise a plurality of discrete heating elements that are arranged with regard to the linear distribution of the bristles. For example, disclosed are heated applicators that have a specified number of discrete heating elements per bristle turn, or per length of core, or per bristle, that number being constant or variable over the length of the core. The use of a plurality of discrete heating elements that are arranged with regard to the linear distribution of the bristles, improves the heating efficiency of the device. Here again, however, the heating elements are distributed, albeit discretely, along the rod or stern of the applicator. The product to be heated is located on the lash grooming elements, i.e. bristles. Heat must travel by conduction from inside the rod or stem to the bristles and into the product. In the process, heat is lost to materials that don't really need to be heated. Product heat up times and power consumption are adversely affected. For these reasons, commercial viability has remained low. There remains a need for a heated cosmetic applicator, in particular a heated mascara applicator, having improved heating capabilities.